R32 Gtr Warm Start Problem

[Cosa]

Having a few problems with the car starting after being driven. Cold starts first go, after being driven, even upto 5-6 hours later, it will not crank over first go, need to play with the peddle a little or just keep cranking till it starts.

Ive done a few searches, from what i can find, i think it might be one of these: ignition module, coil packs, or coil pack loom. I changed the plugs about a week ago, they were very clean, the motor is running pretty lean at the moment.

I have also been told it might be o2 sensor, however it's not misfiring when on boost, and hasnt showed the signs of o2 failure from what i have read. Am i on the right track with what i mentioned above?

The car is reasonably stock, it has had a remap, running 14psi, 044 fuel pump, full 3inch exhaust + hi flow cat, adjustable cam gears, and pods.

[Dose Pipe Sutututu]

Dirty injectors could come to play as well, with the car warm, the injection gets trimmed so the mixture is quite lean, and having clogged injectors adds to it.

If you're finding it easier to start whilst pumping your throttle, then that may be your answer, dirty injectors. Just rip them out and get them cleaned.

If the car doesn't start, try unplugging both AFM and see if the car starts.

[Cosa]

I had the injectors and fuel rail cleaned, and starter motor rebuilt about a month ago.

This problem started once i had that work done, however i might not have noticed since the starter motor was on its way, so it wouldnt crank first go anyway.

Edited September 16, 2009 by Cosa

[blind_elk]

How many fn times does it have to be said - THE O2 SENSOR HAS NOTHING TO DO WITH STARTING OR BOOST PERFORMANCE!

While the ignitors are known to be suspect with age and heat, ordinarily they will play up under all running conditions. And if a coil is going to misbehave, it will do it all the time, not just starting.

Does sound like dirty injectors not delivering enough fuel at hot start.

[Cosa]

It cant be dirty injectors since they have been cleaned.

I also noticed something else, the car idles at around 1100-1200 rpm, from what i understand this should be about 900.

since the car starts fine if i give it a little throttle i was thinking it might be a possible TPS problem?

I have also read that once you have your injectors cleaned, re-setting the ecu is a good idea.

[BoostedBarge]

If it's running at 1100-1200 rpm at idle, then it's likely you have a vacuum leak somewhere. Since you just had your injectors out, that would be the first place I would look. Get some carby cleaner and spray it around the base of the injectors. If you notice the revs drop when you spray a particular place, then you have found your air leak Also spray around the inlet manifold gasket. This let go on my car and caused it to idle pretty badly. Did they replace the injector o-rings when they cleaned the injectors?

[Cosa]

Yes, they replaced the o-rings.

The only reason they were taken out was due to a leaking injector. I will try what you mentioned, and hopefully i can find the problem.

[Cosa]

Problem has been narrowed down to TPS.

Tried to remove top screw on the TPS and it snapped going to have to drill and tap it out, hopefully the bottom screw dosn't snap.

I am hoping that adjusting the TPS will solve the issue. I have also read that after having injectors cleaned it is good practice to reset the ECU. Is this true? Would this affect my remap? Currently have a SPL Computer Brain by Central 20 racing team in there. Tried to look it up, couldnt find much about it.